It’s possible that there is a problem with the file(s) that store the extensions registry.

Type about:support in the address bar and press enter.

Under the page logo on the left side, you will see Application Basics. Under this find Profile Folder. To its right press the button Show Folder. This will open your file browser to the current Firefox profile. Now Close Firefox.

Windows: Show Folder; Linux: Open Directory; Mac: Show in Finder

Linux: Under the page logo on the left side, you will see Application Basics. Under this find Profile Directory. To its right press the button Open Directory.

Delete all extensions* files and compatibility.ini in the Firefox profile folder to reset the extensions registry.

• https://support.mozilla.org/kb/Profiles

New files will be created when required.

After, restart Firefox.

See "Corrupt extension files":

• http://kb.mozillazine.org/Unable_to_install_themes_or_extensions

• https://support.mozilla.org/kb/Unable+to+install+add-ons

+++++++++++++++++++++++++++ You will have to approve the updating one last time.

Hi Animal81369,

I understand you are having issues adding icons for your extensions to the toolbar.

Here are some similar solutions in relation to yours from our valued contributors: Add on icons not showing next to the search bar.

If you haven't already, you can further customize Firefox by dragging your favorite extensions to the toolbar or overflow menu.

This is done by:

1. Clicking the top right menu in the browser.
2. Click customize.
3. Dragging individual extensions in the list to either side of the toolbar.
4. Check if any of your extensions are in the overflow menu

Supporting article: Customize Firefox controls, buttons and toolbars

Let me know if this helps.

Do you still see these extensions listed on the about:addons page (Add-ons -> Extensions)?

You can try Restore Defaults on the customize page.

You can also try to disable and re-enable one of the extensions to see if that restores the toolbar button and try a new window.